1. Field of the Invention
The present invention relates to an electrical connector with post member for opening a shutter of a mating connector.
2. Description of Related Art
Electrical connectors are widely used for making electrical contacts within an electrical system or between electrical systems. In a typical arrangement, an electrical connector has a mating connector fitting section with a plurality of electrical contacts therein. The mating connector fitting section is configured to fit in a mating connector. However, when the mating connector is not fitted into the mating connector fitting section, the mating connector fitting section is exposed. Thus, foreign matter may enter the exposed mating connector fitting section and adhere to the contacts, whereby electrical connection may be interrupted or compromised when the mating connector is fitted in.
To protect the electrical connector from foreign matter, it may be provided with a shutter member to cover the mating connector fitting section. The shutter member is configured to freely open and close.
An electrical connector assembly with such a shutter for protecting from foreign matter generally comprises a receptacle and a plug that is mating with the receptacle. The receptacle has a plug fitting section and a shutter covering the plug fitting section. The plug has a post member for opening the shutter to expose the plug fitting section of the receptacle, and a mating portion for being fitted into the plug fitting section. Wherein the post member is usually a pair of post pins. However, for opening the shutter to expose the mating portion of the receptacle and permit the mating portion to enter, the post member is required to reach the shutter before a top face of the mating portion. Thus the post member has to stand higher than the top face of the mating portion along a mating direction of the plug. That requires a heightened receptacle for receiving the whole post member. Thus the dimension of the assembly will increase, which falls short of presently increasing requirement of size-minimizing of electrical component. If not heighten the receptacle, when the plug is received in and electrically connecting the receptacle, the post member will extend beyond a bottom face of the receptacle along the mating direction, into a printed circuit board (PCB) on which the receptacle is mounted. That requires the PCB to provided recesses to receive a peak of the post member that goes beyond the receptacle. This requirement will complicate a layout of the printed circuit.
Another such kind of electrical connector assembly with post member is disclosed in Chinese Patent Application Publication No. 1291808. The connector assembly disclosed has a similar structure to the above-described assembly except for having an elastic post member. The elastic post member comprises a pair of posts, each of which is driven by a coil spring and movable along the mating direction. So while mating the plug and the receptacle, tip portions of the posts come into abutting bottom faces of post-receiving recesses in the receptacle, so that the coil springs are compressed, making the posts completely received in the receptacle but no longer extending into the PCB. Now there is no need to heighten the receptacle or provide recesses in the PCB for receiving the post member. That's up to the requirement of minimizing the dimension of the assembly and simplifying the layout of the printed circuit.
However, as the post member is driven by the coil spring, if the spring is not strong enough, a force provided by the post member may be insufficient to open the shutter or may not ensure the shutter be opened fully and properly, especially after repeated employment. But if the spring is very strong, when the tip portion of the post comes into contact with the bottom face of the post-receiving recess in the receptacle during mating the plug and the receptacle, the coil spring is compressed and producing a strong force F1 against the post, thus the being inserted plug has to resist both the force F1 and a friction force F2 produced between the mating portion of the plug and the plug fitting section of the receptacle, which increases the difficulty of the mating action. Moreover, the exist of the force F1 between the mated plug and receptacle will result in the plug apt to disengage with the receptacle, or even cause the plug to be pushed out once if the force F1 is greater than the friction force F2.
To overcome above-motioned problems, a new connector with an improved post member is desired.